Automatic return-feed for milling-machines.



No. 731,678. PATENTED JUNE 23, 1903.- G. HAKES 6: F. I. CARTER.

AUTOMATIC RETURN FEED FOR MILLING MACHINES.

APPLICATION. FILED FEB. 13. 1903.

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No. 731,678. I PATENTED JUNE 23, 1903.

- c. HAKES & F. P, CARTER. AUTOMATIC RETURNFEED FOR MILLING MACHINES.

APBLIOATION II-LED FEB. 13. 1903.

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OFFICE.

CURTIS HAKES AND FRANKLIN P. CARTER, OF WIN STED, CONNECTICUT,

ASSIGNORS TO THE CARTER -& HAKES MACHINE COMPANY, OF WIN STED, CONNECTICUT, A CORPORATION OF CONNECTICUT.

AUTOMATIC RETURN-FEED FOR MILLING-MACHINES.

SPECIFICATION formingpart of Letters Patent N n. 731 ,678, dated June 23, 1903. Application filed I'ebruary13, 1903. Serial No. 143,268. No model.)

To all whom it nut/y concern.-

Be it known that we, CURTIS I'IAKES and FRANKLIN P. CARTER, citizens of theUnited States, and residents of Vinsted, in the county of Litchfield and State of Connecticut, have Machines, of which the following is a full,

I clear, and exact specification. I

This invention relates to improvements in means for automatically returning the work tables of milling machines from the position in which they stop atthe completion of the work to the position in which the work is most readily removed from the machine and replaced with a new pieceof work to be operated upon, the object'of the invention bemg to provlde asimple, inexpensive, andeflithis class and which can cient mechanism for this purpose which will cooperate with the already existing feed and driving mechanism of standard machines of also be manufactured independently of those machines and be sent out and applied to numerous machines of this class already in use. j

Figure l of the drawings is a rear View of the table and cooperating mechanism of a milling-machine of a wellknown type to which the present invention is shown to be applied. Fig. 2 is a side view projected from Fig. 1. Fig. 3 is a side view projected from the right side of Fig. 1. I

The work-carrying table 5 in machines of this class is fitted to slide longitudinally on a carriage 6, which is mounted to slide upon the to the move ment of the table 5 to enable the latter to be adjusted laterally, the carriage being clamped in its adjusted position when the machine is at work. The bed 7 is supported by suitable legs 8 an d carries the cutter-drivin g mechan ism, (not herein shown,) which is connect-ed by suitable gearing with the worm-shaft 0, the worm portion 10 of which is long enough to permit of the abovedescribed adjustable transverse movement of the carriage 6 in a direction longitudinally of the worm-shaft. That carriage is provided with a worm-gear 11, having behind it a spur-gear 14, both mounted upon the shaft 15, journaled in the carriage 6; That carriage has also journaled upon it the feed-screw 13, which engages with and useful Improve bolted to the bed of the machine;

a nut appurtenant to the table 5, the screw being provided with a pinion 12, which meshes with the spur-gear on the shaft 15. That shaft has fixed upon it the bevel-gear 16, meshing with the bevel-gear 17, which is splined upon the shaft 18, so as to move longitudinally thereon with the transverse movement of the gear 16, due to the lateral adjustments of the carriage 6. The shaft 18 is journaled in the bed 7 and at its outer end is provided with a handwheel 19, by means of which the shaft 15 and its connected feed-screw 13 may be rotated to feed the table by hand in either direction. I The power or. automatic feeding movement of the table 5 is communicated through the worm 10 of the worm-shaft'9, which is connected bysuitable gearing with the driving-pulleys or gearing of themachine.

The worm-shaft 5) is mounted in swiveling bearings, which permit it to be raised and particular machines mainly in details of construction which are immaterial to the present invention. In the present machine the wormshaft 9 is held into engagement with the wormgear by means of the cranked lever 2ll, which is pivotally mounted upon thestud 22, fixed in the lower end of the bracket 23, which is The upper end of that bracket is provided with a stud 24, upon which is pivotally mounted thelatchdog 25, provided with a shoulder 20, which engages with the upper end of the lever 21 to hold the worm-shaft 0 in driving relation to its worm-gear 11, as shown in Fig. 1, the worm being journaled in a swiveling bearing 28, mounted on the lower end of the lever 21. The opposite or right-hand end of the latch 25 projects into the pathway of a knock-off dog 29, which is mounted ina T-slot extending longitudinally of the table 5, so that the dog may be adjusted to anydesired position for stopping the feed'of the carriage, which is accomplished by the dog riding over and depressing the adjacent end of the latch 25, thus'fre cing the lever 21, the weight of the worm-shaft 9 carrying the lever far enough to drop the worm-threads 10 out of engagement with the worm-gear 11. A stop-pin 30 for they lever is provided in the bracket 23,

and the end of the latch 25 is preferably extended far enough to overlie the upper end of the lever 21 throughout its extent of travel. The mechanism as thus far described is that of the ordinary and well-known feed and .by the power-feed, which may be thrown in by moving the lever 21 to its latched-up position. (Shown in Fig. 1.) The feed, however, is usually thrown in by meansof a lifter or toe-piece 65, fixed on the shaft 66, which extends through to the front of the bed and is provided with a handle'67, convenient to the hand of the operator. When the power-feed is thrown out at the end of the cut, as determined by the setting of the dog 29, the table is commonly returned by hand by means of the hand-wheel 19 to enable the finished piece of work to be taken out and a new piece substituted. The devices of the present invention by which this returning movement of the table is accomplished by power automatically will now be described. This improvement, all of which can be manufactured separately and applied either to machines in course of construction or to machines already constructed or in use, is an independent driving mechanism connected with the shaft 18 and having a clutch or belt-shifting mechanism operated by dogs on the table 5. In the construction herein illustrated the mechanism is driven by a belt 32 from any convenient counter-shaft to the pulleys and 34, turning loosely upon the stud 35, which is supported and clamped in the sleeve 36, mounted upon the stud 37, which is clamped in any convenient way, as by the nut 38 and the bracket 39, to the leg 8 of the machine, thereby enabling these driving devices to be adjusted to adapt them to variationsin existing machines. The stud 35 is longitudinally adjustable in the sleeve 36, being clamped therein by means of the screws 40, and the sleeve 36 is adjustable longitudinally upon the stud 37, being set to place by means of the screws 41. The pulley 33 has an extended hub or sleeve t2, upon which is mounted the sprocket 44, provided with the flanges 46, which are pinned to or integral with the sprocket, so as to turn therewith.

This sprocket is frictionally driven by means of friction-washers 45, of leatheror other suitable material, one of which is placed between the interior flange of the sprocket and the adjacent face of the pulley-hub, while the other sprocket 14 drives a chain 51, which in turn drives the sprocket 52, which is keyed or otherwise secured upon the shaft 18 or the hub of the hand-wheel19, so that when the belt 32 is upon the pulley the shaft 18 is driven friction ally in a direction to return the table 5.

As a means for moving the belt 32 back and forth upon the pulleys 33 and 34 a belt-shifter 54 is coupled, by means of the clamping-yoke 55, to the connecting-rod 56, which is supported in the bracket 57, mounted upon the rearward side of the bracket 23. The other end of that rod is connected to the lever 59, which is pivotally mounted upon a stud 60, attached to the carriage 6. The upper end of that lever is in the path of movement of two dogs 58 and 61, which are fitted for longitudinal adjustment upon the rearward side of the table and are abjustably clamped thereon in any convenient way, as by means of bolts 62, projecting from the T-slot 63 of the table.

The lower lever-engaging ends of the dogs 58 and 61 are cam-shaped in opposite directions, so that the dog 58 moves the lever 59 to the position shown in that figure when the table reaches the desired limit of its backward or return movement, thereby shifting the belt to 'the loose pulley 34, while the other dog 61 shifts the lever to the opposite position to carry the belt to the driving-pulley 33 just before the knock-oft dog 29 reaches the latch 25. After the belt is thus thrown to the drivingpulley and until the dog 29 disengages the latch 25 and allows the worm 10 to drop out of action the driving-sprocket 14 must slip between its frictional collars 45, since the shaft 18 during that short interval is positively driven by the forward-feeding movement; but as soon as that positive forward-feeding movement is stopped by the disengagement of the worm 10 the sprocket 14 becomes the driver and operating through the shaft 18 returns to the table to the limit of its backward movement, determined by the stop-dog 61, which is set in a position to collide with the lever 59 and shift it to the position shown in Fig. 1 at the proper time, thus stopping the return movement. The clamping-yoke 55 between the belt-shifter 54: and the connectingrod 56 not only enables the belt-shifter to be set to the right position relative to the pulleys 33 and 3+1, but also permits the connecting-rod 56 to be shifted laterally with the transverse adjustments of the carriage 6 upon the bed 7.

By mounting the sleeve 36 for longtudinal adjustment upon the stud 37 the pulleys 33 and 34 may be adjusted to suit the length of the chain 51 and to take up the elongation thereof due to wear.

In many machines as, for example, in metal-planing machinesthe movements of the platen or table are automatically reversed by clutch or belt-shifting devices, which are primarily operated by the movement of the table itself, the end of the movement in one direction operating to disengage the clutch or belt which drives it in that direction and to ICC throw into engagement the belt or clutchin which the forward-feeding movement is slow, it would usually happen that devices of the class mentioned would do no more than stop the forward-feeding movement without throwing in the return-feeding device, for

the obvious reason that after stopping the forward driving mechanism there would be no force left in operation to effect the engagement of the return driving devices.

employed for slow -moving beds or tables, suchas a spring, which is compressed by the last endof the movement, and thus stores up energy which continues in operation the force of the moving bed after the latterhas stopped andputs into engagement the return-feeding mechanism. Such devices are, however, liable to be more or less trappy and difficult of adjustmentto different conditions of load or service.

By substituting pulleys of suitable size for the sprockets 44 and 52 a belt may be employed in place of the chain 51; but we prefer both on account of the size of the parts and for greater positiven'ess of action to employ chine in operation thereon. The time saved by the employment of this invention in automatically returning the work-tables to their starting position enables anoperator to attend to a larger number of machines than was hitherto possible and also enables him to do so with less fatigue, since the physical exertion formerly required for returning these tables constituted by far the most laborious part of the task of such an operator.

The automatic return'movement of the table also gives a better visible indication than heretofore to the operator,- that the machine requires his attention, and thus saves time in this respect also, since it often happens work.

that the operator fails to see or hear the fall of the worm-shaft out of engagement, which is the only signal heretofore given in machines of this class of the completion of the Furthermore, particularly in -work which cannot be fed entirely past and out of engagement with the cutter, the automatic returning movement prevents the continued cutting action of the cutter after its work should be stopped, thus enabling work of Various devices are employed to overcome this well-. known characteristic of such devices when "a CD and means for putting the frictional driving mechanism in operation just prior to the completion of the forward movement of the table.

2. In a milling-machine, the combination of forward-feeding mechanism for the table,fric

tional driving mechanism for returning the table, and means operable by the forward movement of the table for putting the frictional driving mechanism into and out of operation just prior to the conclusion of the forward-feeding movement of the table.

3. The combination with a milling-machine table, of independently-driven forward and return feed mechanisms, a frictional driving connection between the return-feed mechanism and the table, and means operable by the forward-feeding mechanism prior to the completion of its movement for putting the returnfeed mechanism in operation.

4. In a milling-machine of the class specified, in combination with the. table-feeding mechanism thereof, a returm feed mechanism having a frictional driving engagement with the table, a pulley therefor driven by an illdependent belt, and means operable by the movements of the table for shifting the belt to and from the said pulley just prior to the com- 'pletion of the respective forward and backward movements of the table.

5. In a millingmachine, in combination with the table-feeding mechanism thereof, a pair of sprockets and a chain connected therewith, a pulley driven independently of the machine, and having a frictional engagement with one of the said sprockets, and means operable by the table for starting the said pulley in operation just prior to the completion of the feeding movement of the table.

6. In a milling-machine of the class specified, in combination with the return drivingshaft 18 thereof, a sprocket mounted thereon, an independentlydriven pulley 33,a sprocketwheel mounted to be driven frictionally by the pulley, a chain for connecting the two sprockets, anda shifting device operable by the table before the completion of its respective movements for putting the pulley into and out of operation.

7. In a milling-machine of the class specified, in combination with the table-feeding mechanism thereof, a frictional return driving mechanism therefor, comprising a supportingbracket for attachment to the machine, a pair of pulleys mounted upon the bracket, and driven by abelt independently of the forwardfeeding mechanism, a sprocket-wheel in frictional driving engagement with one of the pulleys, a sprocket for attachment to a shaft of the feed mechanism, a chain for connecting the two sprockets, and a belt-shifting device mechanism,a chain for connecting the sprockets, a belt for driving the pulleys, belt-shifting' mechanism forshifting' the belt from one pulley to the other, and a pair of dogs appurtenant to the table for operating the belt shifting device.

Signed at Vinsted, Connecticut, this 20th day of January, 1903.

CURTIS I-IAKES. FRANKLIN P. CARTER.

WVitnesses:

ARTHUR J. LA MONTAGNE, CARL J. NYMAN. 

